The present invention relates to a lockable cap that is attached to a locking device mounted on a door plate or the like closure means, and allows setting and opening operation of the locking device when an openable cover of the cap is opened by opening a key-operated lock disposed in the cap for locking the cover.
Lockable caps are known as means that are attached to a locking device mounted on a door plate and allow setting and opening operation of the locking device when an openable cover of the cap is opened by opening a key-operated lock disposed in the caps for locking the cover. The lockable caps, when opened by opening the key-operated lock therein, expose an insertion opening, through which a lock operation means such as a detachable handle is inserted and rotated, to thereby lock or unlock the door.
With the conventional lockable caps of such a structure, however, the key slot of the key-operated lock extends horizontally, and the key is inserted into the key slot from the front side of the cap. This structure of the lock inevitably thickens the entire cap, and causes intrusion of water inside through the key slot, fomenting corrosion of the interior parts.
The present invention aims to solve the above problems of the conventional lockable caps. It is therefore an object of the present invention to provide a lockable cap having a reduced thickness of the entire structure including the key-operated lock.
It is another object of the present invention to provide a lockable cap that can prevent intrusion of water and dust inside.
It is yet another object of the present invention to provide the lockable cap of the above type with a simple structure at low cost.
According to the present invention, there is provided a lockable cap comprising:
a base having an opening penetrating through said base plate,
an openable cover pivotably mounted on said base for releasably covering said opening,
an elastic member for elastically thrusting said cover in an opening direction for exposing said opening,
a latch member for retaining said cover in a closed position with respect to said base against elastic thrust applied by said elastic member,
a key-operated lock disposed in said base,
a key for setting and opening said key-operated lock, and
a latch releasing member attached to said key-operated lock for releasing said latch member to open said cover when said key is inserted into said lock to open.
According to this structure, insertion of the key into the key-operated lock causes the latch releasing member to advance with the key, which advancement in turn presses the latch member toward latch releasing direction to disengage the latch member from the openable cover, allowing the cover to open.
Then the elastic thrust of the elastic member assists in pivotally displacing the cover away from the base to expose the opening, thereby allowing insertion of a lock operation means through the opening for operating the locking device placed on the rear side of the cap to lock or unlock the door. The key may be drawn out of the lock when the key-operated lock is opened, and the latch member as well as the latch releasing member automatically returns to its initial position.
After the setting or opening of the locking device is completed, the lock operation means is drawn out of the opening. The openable cover is manually rotated for closing the opening, and pressed further downward against the thrust of the elastic member. The openable cover is then held in a closed state by the latch member, which state is kept even after the manual pressing is removed.
The lock operation means may be a conventional detachable handle having a boss or a recess of a variety of shapes including triangular, rectangular, or polygonal shape, and adapted to be inserted into an operation slot or fitted on an operation shaft of a locking device.
The elastic member may be an elastic seal in the form of a ring or plate capable of covering the free end or the entirety of the opening. The elastic member provides water-tight seal at the opening when the openable cover is closed, and elastic thrust for assisting in opening the openable cover, when the latch member is released, to the extent that the latch cannot re-engage with the cover.
The key-operated lock may be a lock of a key-insertion type containing pins or a corrugated plate. By structuring the lock to have the key inserted upwards from below the lock, the entire cap may be made thinner and intrusion of water and dust may be prevented.
Further, by providing in the key insertion port a shutter that can be opened upon insertion and draw of the key, the intrusion of water and dust through the key insertion port may be prevented more effectively.